Relationship between dietary energy level, silage butyric acid and body condition score with subclinical ketosis incidence in dairy cows.

Subclinical ketosis is one of the most prevalent metabolic disorders that usually occurs in cows during the first weeks of lactation. This study investigated the relationship between energy level, body condition score and silage butyric acid with incidence of subclinical ketosis (SCK) in dairy cows during the first month of postpartum. Fifty healthy pregnant Holstein cows from 10 commercial dairy farms were studied. Whole blood β-hydroxybutyrate (BHBA) concentration equal or more than 1,400 µmol/L, at least in two successive blood samplings was considered as SCK. The mean plasma β-hydroxybutyrate concentration of SCK cows was 1,932 µmol/L whereas that for the healthy cows was 770 µmol/L. Diet nutrient was significantly affected by the farms studied. Crude protein, net energy for lactation, and non-fiber carbohydrates contents of the diets were lower, whereas that of neutral detergent fiber was higher than those recommended for lactating cows. The effect of farm on pH, lactic acid, propionic acid and lactic acid to acetic acid ratio of corn silage was significant. Effect of net energy for lactation was significant on SCK incidence. The incidence of SCK was not affected by body condition score, butyric silage, crude protein and non-fiber carbohydrates of the diets. Results show that the best way to prevent or minimize the incidence of SCK in dairy farms under commercial farming conditions as that of the present study would be to provide sufficient dietary energy to meet the needs of the cows, especially during the first month of postpartum when the SCK prevalence is normally high.